TH200-4R Transmission

[Ray K.]

My '82 has a carbureted GM crate 350 and TH200-4R automatic (16 bolts fasten the pan, shaped roughly like "Nevada"). The car shifts too early in normal driving, going from one gear to the next at too low an RPM. I have taken to shifting manually to prevent damage to the transmission. I know next to nothing about automatics, but I have read about the "detent cable" and/or "kickdown cable" that must be properly adjusted or damage can occur. Is misadjustment of this cable causing my car to shift early?

Also - does the '82 Avanti have a computer, and is the transmission computer-controlled?

[adamderosa]

Ray-

It sounds like the TV cable may be out of adjustment or broken. (the TV cable goes from the carb to the trans) To adjust it, press in the adjustment button on the cable housing sleeve near the carb, and press the inner sleeve of the cable housing back towards the firewall. Now, release the adjustment button and move the throttle to to wide-open. You should hear the cable adjuster click as it sets. Then take a test drive and see if this helped. If this is un-clear, take a look in a GM shop manual, once you see it it's easy to do.

In '82 I believe the torque converter lock-up was controlled by the computer.

Hope this helps,

Adam

[Ray K.]

Ray-

It sounds like the TV cable may be out of adjustment or broken. (the TV cable goes from the carb to the trans) To adjust it, press in the adjustment button on the cable housing sleeve near the carb, and press the inner sleeve of the cable housing back towards the firewall. Now, release the adjustment button and move the throttle to to wide-open. You should hear the cable adjuster click as it sets. Then take a test drive and see if this helped. If this is un-clear, take a look in a GM shop manual, once you see it it's easy to do.

In '82 I believe the torque converter lock-up was controlled by the computer.

Hope this helps,

Adam

[Ray K.]

Ray-

It sounds like the TV cable may be out of adjustment or broken. (the TV cable goes from the carb to the trans) To adjust it, press in the adjustment button on the cable housing sleeve near the carb, and press the inner sleeve of the cable housing back towards the firewall. Now, release the adjustment button and move the throttle to to wide-open. You should hear the cable adjuster click as it sets. Then take a test drive and see if this helped. If this is un-clear, take a look in a GM shop manual, once you see it it's easy to do.

In '82 I believe the torque converter lock-up was controlled by the computer.

Hope this helps,

Adam

That was easy! The first time I adjusted it, the car shifted too late - 2500-3000 RPM in normal street driving. I backed the cable off a bit, and now it shifts perfectly.

Thanks, Adam

Ray